A two-year-old Mississippi girl born with HIV still shows no evidence of the disease in her blood, according to a study published in the New England Journal of Medicine.

The girl’s physicians say she likely contracted the virus in the womb, and within days she was confirmed to be HIV-positive. In hopes of controlling the infection, the girl was given high doses of three antiretroviral drugs 30 hours after birth and remained on the antiretrovirals for about 15 months.

Experts say timing of the intervention, not the drugs or amount of drugs used, may deserve more emphasis in controlling the infection, CNN reports.

Researchers announced in March that the girl was the first child “functionally cured” of HIV, meaning standard tests can’t detect the virus in the blood and lifelong treatment isn’t necessary.